As part of the SBIR Phase I effort, Nanoparticle Biochem Inc has successfully completed detailed therapeutic efficacy studies of NBI-29 (GA-198AuNP; GA = gum arabic) in prostate tumor bearing mice and toxicity studies of the non radioactive surrogate of NBI 29 in pigs. In order to clinically translate NBI-29 for treating prostate tumor human patients, the objectives of this SBIR Phase II proposal will involve: (i) development of quality control methods for the optimized final formulation of NBI-29 to meet the standards of safety, identity, strength, quality and purity required for investigational drugs; (ii) determination of the biodistribution and radiation dose delivered to normal organs from NBI-29 released from the prostate gland in normal dogs; (iii) determination of diffusion and retention of NBI-29 in prostate gland in dogs; (iv) development of intra-prostate CT-guided multi-injection protocol to maximize the homogeneity of the radiation dose delivered throughout the prostate gland in normal dogs; and (v) evaluation of therapeutic efficacy in prostate tumor bearing dogs. The completion of toxicity/therapeutic efficacy in dogs, as envisaged in the SBIR Phase II effort, will allow filing of an IND application with the US FDA to commence Phase I clinical trials in human prostate cancer patients.